A new method of predicting the time-variability of product heat load during food cooling — Part 2: Experimental testing

Abstract

An ordinary differential equation (ODE) method of predicting the heat load-time profile of cooling and freezing food product has been developed and tested against finite difference (FD) predictions for a selection of shapes. To test both the FD calculation and the ODE method against reality, a technique has been developed to measure freezing food product heat load in an experimental freezer using the difference in temperature between the air flowing onto and off the product. Heat balances for the experimental runs were generally within 10% of their expected values. When the FD and ODE heat load predictions for a meat carton shape were compared with measured data, the predictions matched the real values to within the experimental uncertainty. The ODE heat release predictions for lamb and sheep carcasses were also found to be within about 10% of the experimental data during most of the process, although it was necessary to modify the value of the one new parameter in the ODE method to deal with such highly irregular shapes.